冷库节能潜力分析

食品冷冻冷藏属高耗能行业,长期存在着大量不重视能源管理与浪费能源的现象。分别从隔热材料、压缩机能量调节方式、冷凝器系统、油系统以及运行管理等方面,分析了冷库的节能潜力。针对冷库工程设计、工程施工及常规管理工作的技术要求和需要,提出了相应的节能措施。这些措施对冷库企业降低生产成本、节约能耗,具有现实意义。     

适用于字符串加密的全同态加密方案

面对轨道交通能耗逐年递增的现状,我国大力提倡轨道交通节能,并提出绿色轨道交通的概念。针对传统轨道交通空调系统所存在的冷水机组制冷量过剩、冷冻和冷却水流量无法自动调节等问题,本文设计一种新型节能控制系统,对车站冷负荷变化规律进行分析,对系统进行集中监控。利用变频技术和闭环控制系统,计算所需冷负荷,智能控制电机转速,自动调节冷水机组的制冷量与空调末端冷量,使冷却系统处于最节能的工作点。轨道交通空调水系统应用该节能系统后耗电量大幅度降低,从而节约大量能源。     

从物理学角度看节能玻璃

我国正处于建设的鼎盛时期,每年建成房屋近20亿平方米,而能达到国家规定节能标准的建筑只占10％左右;且在即有的约400亿平方米建筑中,95％以上是高耗能建筑。可见,在我国推行节能建筑已刻不容缓。影响建筑能耗最直接的因素是建筑维护结构的保温与隔热性能,门窗又是其中最薄弱的环节。据统计,在建筑中门窗玻璃的能耗约占建筑总能耗的35％左右,因此节能玻璃的应用在建筑节能中具有重要意义。     

LED阵列光源应用于几何光学实验

设计并制作了单色LED、高功率白光LED阵列光源及配套电源,将其应用于普通物理几何光学实验中。在透镜焦距测量实验中,实现了光源和物屏的结合,成像效果好,光源稳定、可调,相比于卤钨灯光源,成本低,且环保、节能,散热小。     

紧凑型节能荧光灯用新型电子粉

介绍一种新型电子粉制备工艺和电子发射性能,及用该电子粉替代三元碳酸盐制成紧凑节能荧光灯后的工作情况。初步测试结果表明该电子粉的电子发射能力和耐离子轰击能力与三元碳酸盐电子粉相当,而分解时放气量少等方面则明显好于三元碳酸盐电子粉,是替代碳酸盐电子粉的较为理想的选择对象。     

热法磷酸生产过程推动力和节能改造的分析

本文以有余热回收的两步法热法磷酸生产系统为研究对象,提出了热法磷酸生产过程推动力及其节能潜力的概念和计算方法,通过对实际生产系统进行的能量分析,说明了考虑过程推动力的能量分析的科学性和实用性。并在分析导致内部(火用)损失主要因素的基础上,提出了两个节能再改造构想,通过对再改造前后生产系统的能量利用、经济效果和环境影响的对比分析,证明了再改造构想具有可行性。     

Yong与节能

Ｙｏｎｇ是在热力学和能源科学中出现的新概念，是评价能量价值的重要参数。它对能源的开发和合理利用具有重大的理论意义和实际意义。文章介绍了Ｙｏｎｇ的概念、Ｙｏｎｇ效率、Ｙｏｎｇ分析法和Ｙｏｎｇ的合理利用。     

高频电流发生器用于电照明的优越性能：电子学使日光灯变革

高频电流发生器用于电照明，在日光灯具中可获得显著的效益。本文通过实验，测试和分析，明确指出它的优越性能，以及节能，长寿命的物理学，电子学的依据。     

我国工业节能潜力与对策分析

我国工业能耗占能源总消费量的71．5％。高耗能工业产品能耗比国外同类产品的先进水平平均高出约40％，这是我国能源利用效率比国际先进水平低约10个百分点的重要原因，因此工业节能对提高能源利用效率和保障能源安全具有重要的战略意义。本文在工业用能现状分析的基础上，着重讨论了未来5年我国在电力、钢铁、化工、水泥和有色金属等重点...     

Radial vibration and ultrasonic field of a long tubular ultrasonic radiator

The radial vibration of a metal long circular tube is studied analytically and its electro-mechanical equivalent circuit is obtained. Based on the equivalent circuit, the radial resonance frequency equation is derived. The theoretical relationship between the radial resonance frequency and the geometrical dimensions is studied. Finite element method is used to simulate the radial vibration and the radiated ultrasonic field and the results are compared with those from the analytical method. It is concluded that the radial resonance frequency for a solid metal rod is larger than that for a metal tube with the same outer radius. The radial resonance frequencies from the analytical method are in good agreement with those from the numerical method. Based on the acoustic field analysis, it is concluded that the long metal tube with small wall thickness is superior to that with large wall thickness in producing radial vibration and ultrasonic radiation. Therefore, it is expected to be used as an effective radial ultrasonic radiator in ultrasonic sewage treatment, ultrasonic antiscale and descaling and other ultrasonic liquid handling applications.     

超声去脂原理和高效换能器的设计

本文叙述了超声波对生物组织的微观作用。当超声波的强度超过了生物组织的临界空化阈值,可引起生物细胞的破碎。利用人体组织结构、密度的不同,其临界阈值不同,可实现超声波的可选择性破碎功能。介绍了提高换能器效率的方法和途径。给出了测试结果,减肥仪的整机效率约为73.6%左右。     

Optimization of ultrasonic transducers

The so-called KLM-model for ultrasonic transducers is employed to optimize transducer design. Some new performance characteristics are defined which change monotonically with design parameters. These characteristics are based on the area of the envelope of the echo waveform produced by the transducer and of the corresponding amplitude spectrum. The efficiency of the transducer is defined by the round trip energy factor. The performance characteristics are used in a composite performance measure, which is then employed as a criterion in the optimization procedure. Two transducers are investigated: for medical imaging purposes and for spectral analysis of clinical echograms. The influence of electrical matching, backing impedance, matching layer impedance, bond line thickness and series induction on the optimized transducers is investigated.     

The development of recent high-power ultrasonic transducers for Near-well ultrasonic processing technology

With the reduction of crude oil throughout the world, enhance oil recovery technology has become a major oil research topics, which can greatly increase the recovery ratio of the crude oil before the dawning of renewable energy era. Near-well ultrasonic processing technology, as one new method, has attracted more attention for Enhanced Oil Recovery due to its low cost, good applicability and no environmental pollution in recent rears. There are two important relevant aspects about Near-well ultrasonic processing technology: (a) how to enhance the oil flow through the rocks into the pumping pool and (b) how to reduce the oil viscosity so that it can be easier to pump. Therefore, how to design a high-power ultrasonic equipment with excellent performance is crucial for Near-well ultrasonic processing technology. In this paper, recent new high-power ultrasonic transducers for Near-well ultrasonic processing technology are summarized. Each field application of them are also given. The purpose of this paper is to provide reference for the further development of Near-well ultrasonic processing technology.With the reduction of crude oil throughout the world, enhance oil recovery technology has become a major oil research topics, which can greatly increase the recovery ratio of the crude oil before the dawning of renewable energy era. Near-well ultrasonic processing technology, as one new method, has attracted more attention for Enhanced Oil Recovery due to its low cost, good applicability and no environmental pollution in recent rears. There are two important relevant aspects about Near-well ultrasonic processing technology: (a) how to enhance the oil flow through the rocks into the pumping pool and (b) how to reduce the oil viscosity so that it can be easier to pump. Therefore, how to design a high-power ultrasonic equipment with excellent performance is crucial for Near-well ultrasonic processing technology. In this paper, recent new high-power ultrasonic transducers for Near-well ultrasonic processing technology are summarized. Each field application of them are also given. The purpose of this paper is to provide reference for the further development of Near-well ultrasonic processing technology     

Modal expansion analyses of ultrasonic Lamb waves generated by electromagnetic ultrasonic transducers

A modal expansion approach has been proposed for investigating generation of ultrasonic Lamb waves by electromagnetic acoustic transducers（EMATs）.Based on the current distribution of the EMAT＇s meandering coil,the formal solution for the Lorentz surface stress applied on the plate surface has been derived.Then the function of the wave-number spectral density of the Lorentz surface stress for generating ultrasonic Lamb waves has been obtained using the spatial Fourier transform.On this basis,with the modal expansion approach for waveguide excitation,the mathematical expression of the Lamb wave＇s mode expansion coefficient has been deduced,which is closely related with the geometrical parameters of the EMAT＇s meandering coil.The mathematical relationship between the Lamb wave＇s mode expansion coefficient and the EMAT＇s geometrical parameters,obtained in this paper,lays a theoretical foundation for exactly analyzing generation of Lamb waves by EMATs.Further,the numerical analyses performed indicate that the Lamb wave＇s mode expansion coefficient can be appropriately adjusted by changing the geometrical parameters of the EMAT＇s coil,and thus the unwanted Lamb wave modes can be effectively restrained.This result provides a theoretical basis for generating a single and pure Lamb wave mode by the meandering coil EMAT.     

模式转换型超声塑焊振动系统的设计

基于弯曲振动理论和耦合振动理论,设计了一种新型大尺寸筒形超声塑焊振动系统。该振动系统由纵向振动换能器及变幅杆、弯曲振动金属圆盘和耦合振动圆筒四部分组成。换能器和变幅杆的纵向振动驱动圆盘的二次弯曲模式振动,圆盘的二次弯曲模式振动激励圆筒的纵向模式振动,实现了工具头在较高频率下谐振。实验结果表明,振动系统的测试频率与计算频率比较符合,在大信号下测试的纵-弯-纵振动模式转换效果很好。研究结果为高频大尺寸超声焊接系统的设计提供了思路。      

Nonlinear ultrasonic phase-conjugate beams and their application in ultrasonic imaging

The latest results of experimental and theoretical research into phase conjugation of nonlinear ultrasonic beams are generalized, and prospects for the development of nonlinear ultrasonic imaging are outlined.     

电磁超声换能器激发超声兰姆波的模式展开分析

提出一种用于研究电磁超声换能器(EM.AT)激发超声兰姆波的模式展开分析方法。从EMAT曲折线圈的电流分布出发,推导出铝板表面洛伦兹切向应力的形式解;对其进行空间傅里叶变换,得到激发超声兰姆波的表面驱动应力之波数谱密度。在此基础上采用导波激发的模式展开分析方法,推导出与EMAT线圈的几何参数密切相关的兰姆波模式展开系数的数学表达式,为严格分析EMAT的兰姆波激发问题奠定了理论基础。数值分析结果表明,通过改变EMAT线圈的几何参数,可对兰姆波的模式展开系数进行适当调整,从而实现有效抑制不需要兰姆波模式的目的,这一结果为采用EMAT激发纯度高的单一兰姆波模式提供了理论依据。